This invention relates to devices used in the carbonated beverage industry and other industries using carbon dioxide, such as fire protection systems, welding, medical and other industries using compressed gases. This technology may have applications in additional other industries, for reasons of simplicity, this discussion will relate primarily to the beverage industry. It is in no way meant to limit the application of this invention to only the beverage industry.
The beverage industry uses carbon dioxide to carbonate and to move beverages from a storage tank to a dispensing area. For beverages such as beer, the beer can be contained in large kegs in the basement or storage room and the taps at the bar can dispense the beer. This method eliminates the storage of beer kegs in the bar area and allows the beer keg delivery and removal to occur in an area other than that in which patrons may be sitting. This type of system has existed for many years. In order to get the beverages from the storage area to the serving area, prior art has used carbon dioxide among other gases. The carbon dioxide is generally delivered as a liquid in large heavy DOT cylinders and hooked to the dispensing system. When the tanks are hooked to the system, a certain volume, generally about one third of the tank, in a one tank system or one third of the tank volume in a multi-tank system is not filled with liquid. This allows the carbon dioxide to boil to a gaseous state. It is this gaseous state that is then used to carbonate and to move the desired beverage from the storage room or basement to the delivery area and provide much of the carbonation to the beverages.
The only problem with this system is that the carbon dioxide tanks must be changed or when the current tanks run out, they must be replaced with new tanks. This can be inconvenient and time consuming. If only one person is working, then they are required to leave the patron area and manually change the tank to allow the refreshments to continue to flow. In addition, delivery of additional filled tanks cannot always occur when they are needed if a user runs out in the late evening or during non-business hours. This problem can be somewhat lessened by using multiple liquid tanks, but this uses more space and can be more expensive to monitor and refill.
To refill or replace a tank, the system must generally be completely shut down, so no beverages can be served, and service or delivery personnel can move the full liquid carbon dioxide tanks into the business and remove the empty tanks. Generally several valves must be shut off while the tanks are changed. The business must wait until the changeover is complete before beverages can be served again.
Some systems exist where the physical changing of the tanks has been eliminated. This is done by delivering liquid carbon dioxide to the tanks or system pre-existing in the businesses. Generally a pump truck delivers the liquid carbon dioxide to a fill line plumbed to the outside of the building. The delivery personnel must then enter the establishment to close and adjust various valves. The system is then shut down and the dispensing of beverages must cease until the filling process is complete. Delivery personnel must then return to the truck and start the pump. They must then carefully watch the system to attempt to determine when the system is full. This can be difficult to determine with any uniformity. Some weeks a business may do very well with beverages and some weeks may not do so well. While an operator may get a general sense, it is difficult to determine without the trial and error method, when the system is full.
Some art uses relief valves to indicate when the system is full. This method of determining when the system is full is wasteful and can result in increased pressure hazards from over filling. Over filling can also result in the system not operating properly.
The system needs to maintain the proper liquid gas ratios and overfilling lessens the efficiency of the system as a whole. When the delivery person determines that the system is full, he/she must then reverse the actions taken on the valves and disconnect the truck from the system. While these types of systems do eliminate much of the inconvenience of physically changing out tanks, there are still significant disadvantages to this liquid delivery system common in the art.
Some prior art uses o-rings in the valving and extensive connections and valves. These types of o-ring systems are notorious for failures. Once a system fails, the business may have no carbon dioxide for serving beverages. A call for maintenance may go unanswered if not during regular business hours. Thus, the beverage system may not be operational. The other failure mode of the o-rings or extensive connections or valving is to develop a leak. This causes gaseous carbon dioxide to leak in the storage area and depending on the size of the leak can be costly and hazardous.
For the foregoing reasons, there is a need for a liquid delivery system that would not require the delivery personnel to enter the business to shut/adjust valving before and after delivery of the liquid. There is also a need for a system that would allow the delivery at any time of day or night without any contact with the personnel inside the business. A system that aided in delivering the proper amount of liquid while also lessening the hazards associated with over filling is needed. Also needed is a system that would allow the business to continue using the beverage delivery system without interruption even when the system is being filled. This will result in more sales and less inconvenience to the business. A system that doesn't vent the liquid carbon dioxide to the atmosphere as a means of determining a filled system will also result in less waste, less cost to both the beverage and the delivery businesses and less potential hazards. A system that does not use o-rings and simplifies the number of connections and valving is also very desirable.